The development of RFID systems has been fueled by advances in integrated circuit (IC) technology, which enables significant miniaturization of electronic devices, and recent growth in the popularity of wireless communications, which provides a secure and reliable way for transferring information using RF signals. Typically, an RFID system includes an RFID interrogator (or reader) and one or more RFID tags (or contactless IC cards). In operation, the RFID interrogator generates an alternating magnetic field, which induces electric current in a proximate RFID tag. The induced electric current provides enough power to the RFID tag to transmit a response signal to the RFID interrogator.
Due to relative simplicity and low cost of manufacturing, RFID systems have gained a widespread application. For example, RFID technology is commonly used for personal authentication in passports and other forms of ID. In the transportation sector, RFID cards are used to pay for the use of public transportation and highways. In the retail environment, RFID tags are used for product tracking. In the banking industry, RFID technology is embedded in debit and credit cards. In security applications, RFID cards are used to access secure areas or services. In medicine, RFID technology is used in human implants to monitor various health conditions, monitor prescribed drugs and the like.
The growing demand for RFID products has resulted in development of numerous proprietary and non-proprietary RFID technologies. The proprietary nature of some of these technologies often makes them incompatible with each other. For example, RFID systems manufactured by different vendors may use custom communication protocols and data formats and have different power requirements. Despite industry-wide efforts to standardize RFID technologies, there remain numerous incompatible RFID systems. Accordingly, there is a need for an RFID interrogator interoperable with various RFID tags, which may have different protocols, data formats and power requirements.